Iodine catalyzed simple and efficient synthesis of antiproliferative 2-pyridones.

A simple and efficient method for the selective synthesis of 2-pyrdones from 4H-pyrans using iodine as catalyst and ethanol as solvent was developed. The present method is equally effective for both aromatic and hetero aromatic ring containing 4H-pyrans. The compatibility with various functional groups, mild reaction conditions, high yields and application of inexpensive, readily and easily available iodine as catalyst and formation of 2-pyridones as major products are the advantages of the present procedure. In vitro antiproliferative activity of the final synthesized compounds was evaluated with four different human cancer cell lines (Lung adenocarcinoma-A549, Hepatocarcinoma-HepG2, Breast carcinoma-MCF-7 and Ovarian carcinoma-SKOV3) and normal human lung fibroblast cell line (MRC-5). Compounds 2b showed better inhibition against MCF-7, HepG2 and A549 cell lines (IC50 8.00 ± 0.11, 11.93 ± 0.01 and 15.85 ± 0.04 µM, respectively) as compared with doxorubicin and also 2e showed moderate inhibition against MCF-7, HepG2 (IC50 9.32 ± 0.21 and 20.22 ± 0.01 µM, respectively, cell lines, respectively) as compared with doxorubicin. As many clinically used antiproliferative agents induce apoptosis in cancer cells hence, the 2-pyridone analogues were also tested for their ability to induce apoptosis in MCF-7 cells using the caspases-3 and -9 assays.

Synthesis of cyclic 1,9-acetal derivatives of forskolin and their bioactivity evaluation.

A new series of 1,9-acetals of forskolin were synthesized by treating with aromatic and aliphatic aldehydes using Ceric ammonium nitrate as catalyst and evaluated for anticancer and α-glucosidase inhibition activities. Among the synthesized compounds 2a, 2b and 3a showed potential cytotoxic activity towards human cancer cell lines MCF-7 (Human Breast Adenocarcinoma), MDA-MB (Human Breast Carcinoma), HeLa (Human Cervix Adenocarcinoma), A498 (Human Kidney Carcinoma), K562 (Human Erythromyeloblastoid leukemia), SH-SY5Y (Human Neuroblastoma), Hek293 (Human Embryonic Kidney) and WRL68 (Human Hepatic) with IC50 values ranging between 0.95 and 47.96 µg/ml. Osmotic fragility test revealed compound 3a as non-toxic to human erythrocytes at the tested concentrations of 50 and 100 µg/ml. Compounds 1g (IC50 value 0.76 µg/ml) and 1p (IC50 value 0.74 µg/ml) significantly inhibited α-glucosidase in in vitro system. In silico based docking, ADME and toxicity risk assessment studies also showed discernible α-glucosidase activity for compounds 1g, 1p compared to standard acarbose.

Flavanoids from Caesalpinia pulcherrima.

Two new flavanoids, 5,7-dimethoxy-3',4'-methylenedioxyflavanone and isobonducellin along with 2'-hydroxy-2,3,4',6'-tetramethoxychalcone, 5,7-dimethoxyflavone and bonducellin were isolated from the aerial parts of Caesalpinia pulcherrima. The structures of the compounds were settled mainly by interpretation of their 1D and 2D NMR spectra. Isobonducellin was found to be a homoisoflavanoid containing a cis (Z)-double bond. Antimicrobial activity of the new compounds was evaluated.

A highly convenient, efficient, and selective process for preparation of esters and amides from carboxylic acids using Fe(3+)-K-10 montmorillonite clay.

In the presence of Fe(3+)-K-10 montmorillonite clay as a catalyst, aliphatic carboxylic acids selectively produced the corresponding esters in the presence of aromatic carboxylic acids by treatment with alcohols. Both the aliphatic and aromatic carboxylic acids formed the amides by reacting with the aliphatic amines, but only the aliphatic carboxylic acids yielded the anilides by treatment with aromatic amines. The catalyst is recoverable and recyclable.